08. Extensibly Group Prereqs
Rather than have 'config_requires' and 'install_requires' and
'signature_requires' and 'build_recommends', have a two-level system. This
requires a small bit of reworking now, but is easy to extend later without
adding many top-level keys. Right now (phase)_(verb) is multiplicitive.
Both phases (test, install, configure) and verbs (requires, recommends,
conflicts) can be added easily over time.
* I would also like to see this split better. It recently came up that a
'recommends' list is inappropriate to list optional testing modules,
however as a two-level system, 'test' and 'recommends' might be a better
fit, as 'test_recommends' doesn't exist at the moment. (Barbie)
* This proposal assumes that the downstream consumers will be able to
handle all possible combinations. The implications for the downstream are
multiplicative, even if the encoding in META.yml are not.